Safety device for platen printing-presses.



M. ROCKSTROH. SAFETY DEVICE FOR PLATEN PRINTING PRESSES.

APPLICATION FILED MAY 17, 1911.

Patented Feb. 20, 1912 4 SHEETS-SHEET 1.

M. ROGKSTROH. SAFETY DEVICE FOR PLATEN PRINTING PEESSES.

APPLICATION FILED MAY17, 1911. I

Patented Feb. 20, 1912.

4 SHEETSSHEET 2.

Fig.2

M. ROGKSTROH. SAFETY DEVICE FOR PLATEN PRINTING PRBSSBS.

APPLICATION FILED MAY 17, 1911..

Patented Feb.20, 1912.

4 SHEETS-.SHEET 3.

Fig.5

M. ROGKSTROH. SAFETY DEVICE FOR PLATEN PRINTING PRESSES.

APPLICATION FILED MAY, 1911.

Patented Feb. 20, 1912.

4 SHEETS-SHEET 4.

Fig.

MAX RDCKSTROH, OF KLEIN-SEDLITZ, NEAR PIRNA, GERMANY.-

' SAFETY DEVICE FOR FLATEN PRINTING-PRESSES.

7 Application filed May 17', 1911. SerialNo. 627,656.

interruption of the movement of the roller carriage. I

On printing with platen printing-presses it often occurs that the roller carriage catches on projecting types or packing or spacing material, or that the regular working of the roller carriage is interrupted by paper waste or sheets of paper which have It'may thus occur adhered to the rollers.

that the roller carriage is'fiattened between the printing form and the platen, or that some part adapted'for the movem nt of the roller carriage is broken. According to the present invention such accidents due to the,

interruption of the regular working of the roller carriage are prevented by a machine part which assists in transmittmg the movement and effects the releaseof stop mecha-w braking action or fracture oc-.

nism, on any curring thus automatically-puttlng the press out of operation and applylng' the brake.

In the accompanying drawing Figure 1 is a platen printing press 1n side elevation partlyin section provided with the stopping mechanism, under the conditions of the normal working of the press. Fig. 2 shows the stoppageof the roller carriage and the press out of operation. Fig. 3 shows a front ele- 40 vation of the platen printing press with the parts in question. Figs. 4 and 5 show a constructional form of the machine part,

consisting of two members which on the stoppage of the roller carriage alter their position in relation to one another, andthrowthe press out of operation. Fig. 6 is a side elevation of a platen printing press provided with a modified form of safetydevice in plan. Fig. 7 shows a rear elevation of thesame arrangement. Fig. 8 is a section on the line wm Fig. 6. V r

n In the constructional forms illustrated the connecting rod, which causes the upward and downward movement of the lever of the roller carriage, is employed for effecting the j Y J' v 4 stopping of the machine. For this purpose theconnecting. rod, according to Figs. 1, 2

and 3, consists of two members 7 and 8' which engage with .each other by means of grooves, prisms or wedges, and are pressed Specification of Letters-Patent. Patented Feb. 20, 1912. U

together by means of a spring 10 during the uniform movement of the roller carriage. If, however, in consequence of a fracture or stoppage greater forces arise, the spring, which presses the members of the connecting rod together, is no longer capable of resisting and the parts slide over one another.

The connecting rod therefore shortens or lengthens according to the direction of the forces which occur and the displacement of the members of the connecting rod causes the release of the check action of the disconnecting rod.

1 indicates the roller carriage, which in the known manner is -moved upward and *downward by the rod 2 through the medium of the roller carriage lever 4. The connecting rod consists of the two members? and 8 held pressed together by means of grooves and projections in consequence of the pressure of a spring 10 placed around the bolt 9. On the pivot 17 is rotatably mounted a bell crank lever 16 which during the regular operation of the'press assumes the position shown in Fig. 1, in view of the factthat 1t engages by a knife like lateral projection 18 provided at the upper end of one of its ar 's with a similar projection 20 provided on e connecting rod member .7. ()n the slightest prolongation or shortening of the connecting rod by the variation in position in relation to one another of the members '7 and 8cof the connecting rod, the two knife edges 18 and '20 slide from one another. Againstthe other arm of the bell crank lever 16 rests a pin 15 provided on a lever 14. I

which is'rotatable on the shaft 3. The lever14 is under the action o f aspring 19 and retains its normal posltion as long as the lmife-like projections-l8 and. 20 are in engagement with one another. When forces arise which releasethe members '7 and 8 of the connecting rod from one another then the-connecting rod is either lengthened or shortened. In consequence of this the knife edge 18 of the lever 16 slides from the knifeedge 20 of the connecting rod member '1,

the lever 16 rotates and allows the lever 14, l

which is 'under spring action and engages therewith by means of thepin 15 to rotateconnected together by means of pins 13.

The'resistance of these pins is such that during regular Working they remain in post-.- -tion but on greater forces arising they effect a lengthening or shortening of the connecting rod.

In the constructional form shown in Figs. 6-8 the parts of the rod, which move the roller carriage, are integral with, and form anunstable intermediate member connected thereto of which the variation in length puts the press out of operation. In an arm 40 connected to the roller carriage is rotatably mounted a three-armed lever 29, 37 and .38 to the short arm 37 of which is connected the connecting rod 2 which is moved upward and downward, in the known manner by the lever 4. The upwardly projecting arm 38 of the three armed lever 29 is provlded with a groove 42 with which engages a spring bolt 30 which is mounted in the guide 43v ofthe'carriage 1 and thus retainsthe three armed lever in its normal position. The downwardly projecting arm of the lever 29 engages with its forked end (Fig. 8) with a rib 31 of a rotatable spindle 39 mounted in bearings 32. and 33, the length of said rod corresponding to the travel of roller carriage. At the lower end of the spindle 39 is provided an arm 34 which looks the bell crank lever 35. The bell crank lever is under the action, of a spring 19 which tends to rotate it about its fulcrum 36;iits lower arm projects into the plane of the arm 28 of a bell crank leverof which the other arm 27 engages above the projection 24 of the disconnecting rod 21.

The operation of the device is the fol-- lowing: When abnormal forces arise l the spring pressure of the bolt 30 is no longer capable of retaining the lever 29. This lever therefore rotates on the pivot 41 and moves 55 with itthe rib 31. The spindle 39 is thus rotated about its longitudinal axis and the lower arm 34 thereof is moved laterally, and the bell crank lever 35 loses its support so that, in consequence of the spring 19, it strikes against the arm 28. With the arm 28 the awl 27 rotates about 26, being thus raised f i'om the projection 24 of the disconnecting rod 21, and this latter in the known manner puts the press out of operation and applies the brake.

Instead of retaining the three-armed lever, which connects the connecting rod to the roller carriage, in its normal position by wedge-shaped grooves this could be efl'ected' by pressing the two members )on one another by friction the parts in unstable equilibrium.

In the examples illustrated the puttingout of operation and braking of the press is directly effected by the variation of the 75, position of connect-ing rods, that is, by the variation of the position of the members thereof in relation to one another. The device would, however, also be effective if the fracture of any other part which transmits 3a movement to the roller carriage produces a relative movement, for example, if theplaten abuts against the safety device which operates" the stopping mechanism as is for example provided as on the roller carriage 35 itself or its path. 7

Having now particularly described and 1 ascertained the" nature of my. said invention and in what manner the sameis to be performed I declare that what I claim is 1. Tu a safety device for platen printing presses,the combination with a roller carriage, of means for reciprocating the carriage including pivotally mounted bars hav- 7 ing coacting cam faces arranged to separate said bars upon relative movement of the same longitudinally from their normal position,

a spring for holding said bars in coupled relation, throwout mechanism for the press, and a trip device engaging one of said bars 109 and serving upon separating movement thereof to actuate saidt-hrowout mechanism, substantially as described.

2. In av safety device for platen printing presses, the combination with a roller car 1 5 riage of means for reciprocating the car-=' riage including pivotally mounted bars having coacting cam faces arranged toseparate 'sald bars upon relative movement of the same longitudinally from their normal po- 110 sition,'a spring for holding said bars in coupledvrelation, throwout mechanism for the press, and a trip device having a portion thereof mounted on the pivot of one of said bars andengaging the other of said bars and serving upon separating movement of the bars to actuate said throwout mechanism, substantially as described.

3. In a safety device for platen printing presses, the combination with aroller car- 0 riage, of means for reciprocating the carriage including connecting'bars having coacting cam faces arrangedto separate said bars for relative movement of the same longitudinally from their normal position,

throwout mechanism for the press, and a trip device held by said bars in their normalposition and released thereby when said bars are separated to actuate said throwout mechanism, substantially-as destamilmad4.- 1

4. Ina safety device for platen printing presses, the combination With 'a roller carriage, of means for reciprocating the carriage including coacting cani members with yielding means for holding the same in operative relation and permitting isplacement thereof, throwout mechanism for the press, and a trip device arrangedto be released from. said cam members to actuate 'said throwout mechanism, substantially de 10 "scribed.

I In testimony whereof I have hereunto set my hand in presence of two subscribing Witnesses. '4

MAX ROCKSTROH. V Witnesses; 7 PAUL ARRAs, -.CL KRE SIMON. 

